This invention relates to a tape run speed-changing circuit adapted to be used with a multispeed type tape recorder having cue and review functions.
A tape recorder used in place of a written memorandum offers great advantages, if provided with cue and review functions. The term "cue" denotes an operator's action of effecting the fast forward (FF) mode of a magnetic tape, while listening to the sounds produced from a tape. The term "review" represents an operator'action of carrying out the rewind (RW) mode of the magnetic tape, while listening to the sounds produced from the tape. The cue and review modes of the tape recorder are used to check the contents of data recorded in the tape. Since the operator carries out the cue and review modes to quickly check the contents of the tape while listening to said contents reproduced from the tape, the tape should naturally run at a proper speed. In other words, if the tape travels too slowly, then the check of the recorded data consumes a considerably long time. Conversely where the tape run is unduly fast, it is impossible for the operator to distinctly hear the reproduced sounds. The speed at which the tape runs for the cue or review mode should be properly changed in accordance with the speed at which the tape originally travelled for the recording mode, for instance. Now let it be assumed that data was recorded on a tape, while it was run at a speed of 2.4 cm/s, and there is provided a tape recorder which is so designed as to cause a tape to travel for the cue or review mode at a speed conforming to the above-mentioned recording speed of 2.4 cm/s. Where it is attempted to check data recorded in a tape at a tape run speed of 1.2 cm/s by means of the aforesaid fast tape run type tape recorder at the cue or review mode, then the tape run is so fast that the operator has considerable difficulties in hearing sounds reproduced from said 1.2 cm/s recorded type tape. Conversely where it is attempted to check sounds recorded in a tape at a tape run speed of 2.4 cm/s by means of a tape recorder which is designed to cause a tape to travel for the cue or review mode at a speed of 1.2 cm/s, then recorded sounds are checked with an exceedingly low efficiency.